Veterinary Drugs Residue Methods


Category Steroids
Drug Class Name Melengestrol acetate, a Sythetic Progestone-like compound
Method Title Confirmation of Melengestrol Acetate by APCI/LC/MS3
Method Date 2003/03/18
Method Type Confirmatory, Quantitative
Scope and Application The method is suitable for confirming the presence of MGA in animal fat tissue
Method Summary Ground bovine tissue is mixed with anhydrous sodium sulfate before adding hexane,acetone (80,20, v,v). The fat is melted by incubating the mixture in a water bath (at 55 - 60 degrees celcius). The sample is then filtered through a funnel with small silanized glass wool plug and anhydrous sodium sulphate into a separatory funnel. The sample container is rinsed with hexane and acetonitrile and the contents filtered into the separatory funnel as well. The separatory funnel is stoppered, shaken vigorously and the bottom layer (acetonitrile) collected into a flask. The hexane layer discarded. However, after evaporating the acetonitrile solution to dryness the residue is reconstituted in hexane and the contents cleanedup by column chromatography (involving florisil and silanized glass wool). After washing the loaded column, the analyte is eluted with 75,25 hexane,acetone. The hexane,acetone mixture is evaporated to dryness and the extract reconstituted in hexane which is further evaporated to dryness. The final residue is reconstituted in a sample diluent (55,45 methanol/water plus 0.1 percent formic acid) and pressed through a 0.2 micrometer nylon syringe filter ready for LC/MS3. Separation is done on Agilent/Zorbax XDB C-8 analytical column.
Applicable Concentration Range The minimum proficiency level for MGA here is 12.5 µgkg -1
QC Requirements See attached SOP
Method Source USDA-FSIS
Method SOP PDF icon SOP